Process for producing shrink-resistant wool by treatment with hypochlorous acid and cationic hydrophilic resinous condensation product

ABSTRACT

IN THE SHRINK-PROOFING OF WOOL IT HAS BEEN FOUND THAT A PRODUCT HAVING AN EXCEPTIONALLY VALUABLE COMBINATIN OF PROPERTIES E.G. HANDLE, FLEXURAL PROPERTIES, TENSILE STRENGTH, RESILIENCE AND ELASTICITY IS OBTAINED WHEN WOOLLEN MATERIALS ARE FIRST SUBJECTED TO A UNIFORM TREATMENT WITH HYPOCHLOROUS ACID AT AN ACID PH, THE TREATMENT BEING LIMITED TO THAT WHICH WILL REDUCE THE SHRINKAGE UNDER STANDARDARD WASHING CONDITIONS BY 15-80%, THEN IMPREGNATED WITH A WATER-SOLUBLE CATIONIC HYDROPHILIC RESINOUS CONDENSATION PRODUCT CONTAINING POLYOXYALKYLENE GOUPS IN THE MOLECULE AND FINALLY HEATING THE WOOL WHEN IMPREGNATED WITH SAID CONDENSATION PRODUCT.

PROCESS FOR PRODUCING SHRINK-RESISTANT WOOL BY TREATMENT WITH HYPOCHLOROUS ACID AND CATIONIC HYDROPHILIC RESINOUS CONDENSATION PRODUCT 5 Dennis w 3 1 a J t J h Duhield, soiled. Woollen materials which have been treated in England, assignors to Precision Processes (Textiles) this y do not have a Satisfactory handle it being P Limited, Ambergate, Derbyshire, England ticularly desirable that treated woollen goods should have NO Drawillg- Filed y 1967. 656,339 a handle closely resembling that of similar untreated Claims priority, application Great Britain, July 29, 1966, to goods 34 288/66 Int. Cl. DO6m /36 Various difficulties have been encountered in attempting CL 13 Claims to produce thin films of polymeric materials which were suitably disposed over the surface of the wool fibres to produce shrink resistance. ABSTRACTOF THE DISCLOSURE 15 Amongst the polymeric materials which have recently become available and are of particular interest on ac- In the shnnk'proofing of wool has been fourid h count of their unusual chemicalnature are the condensaa product having an exceptlonauy valuable cPmbmatlfm tion products disclosed in British patent specification No. of Propel-t1? i z s Propemes tenslle 880,897. According to this specification hardenable waterstrength, resilience and elasticity is obtained when woollen sotube condensation productsme produced by condensing materials are first subjected to a uniform treatment with potyamines containing at least two amine nitrogen atoms hyppchlorous 301d an.ac1d the treiltment bemg in the molecule, such as polyalkylene polyamines, with hmlted that Winch wlu.lieduce'the Shnnkage unfier mono and/or poly-functional derivatives of alkylene oxstandardlsed. washmg condltlons y i h ides, more especially alkylene oxides having a molecular pregnated with a water-soluble cationic hydrophilic resweight of 400 to 2000 and then heating the resulting inous condensation product containing polyoxyalkylene condensate with a bifunctional compound containing one .groups in the p and finally .heating the Wool when or more epoxide and/ or alpha-halo-beta-hydroxyalkyl impregnated Wlth sald condensatlon product groups in the molecule. A reaction mixture is obtained theviscosity of which gradually increases. The reaction may then be interrupted and the pH value of the solution T relates the tr?atment of Woollen adjusted to 6 in order to stabilise the condensation product tenals to Improve the shrmk reslstance f in solution. The presence in the molecules of these con- A number of processes known for applying sllnnk densation products of polyoxyalkylene chains results'in res stance to wool. Essentially these are of two kinds. materials having unusual hydrophjhc Properties by virtue Inzone kind of process the wool is sub ected to the action of the van der Waats forces which attract Water mo1e offan' aqueous 9 of one or moreoxidising i cules present .in the atmosphere to the oxygen atoms of P a reagent wh lch acts as a source 9 hypochlorous the chains with the result that electrostatic charges are in aqueous solution such as an alkali metal hypochlorite unable to accumulate upon the surface of the ultimate or dichloroisocyanurate, or alternatively, an alkali metal resin molecules The products are therefore of interest in permanganate or perinonosulphuric acid or an alkali metal 40 the production of coatings having good conductive pro? salt thereof. The action of the OXldlSlng agent may be antes, particularly for the treatmentlof hydrophobic that of a reducmg agent: treatment wlth terials of synthetic origin in use in the textile industry an alkah metal Salt of Sulphurous but they may also be used upon materials of natural Usually the severe oxidative chemical treatments reorigin such as WOOL quired to give a high degree of shrink resistance result We have however found that the use of the said cot-h in a marked denaturingof the wool fibres. This is manidensatton products upon Wool is not without dithculty fested in the deterioration of several essential and charac- Costing is Possible and inter imparts some, slight teristic Properties of the W001 fibre strength, abrasion degree of shrink resistance to the treated wool. However, si elasticitY fiexural rigidity faismess f in our experience, the degree of shrink resistance' imwelght Another dlsadvamage of the oxlflatve f f' parted at acceptable loadings of condensation product is resist treatments when applied to loose knitted fabrics is very small and the degree of covet-age of the fibre surface that, if the fabrics are subjected to severe oxidative by the condensation product is unsatisfactory so that chemical treatments 10W Shrinkage after in on washing the material is little better than untreated tensive Washing, stretchmg'mafy occur on ematerial. It is accordingly an object of this invention In the other kmd of process It has been to i to provide a process which will impart satisfactory shrink fy the surface of the wool fibres by the application thereto resistance to woollen materials using the said condensa; of varying types of polymeric materials which would mask tion Products. the scale structure of the wool, and thus protect the wool According to the present invention there is provided from the action of Washing bathsf y the h P a process for the production of shrink resistant wool Portionby Weight of Polymeric mammals. requlred a which comprises first substantially uniformly treating wool material in order to show a low shrinkage after in- 1 With an aqueous solution f hypochlotous acid at an tensive washing results in a severe deterioration in the acid PH so as to dif the 1 to Such an extent that handle of the fabric and a marked increase in lflexural there is a reduction in shrinkage, when compared with an g y- These two Properties alone h been Sufiicient untreated control which is subjected to the same washing .ensllre that, P to the Present tlme, most P y test, of at least 15%, then substantially uniformly imtreatments of wool intended to impart shrink resistance pregnating the h difi d wool i a watepsoluhle have been of little commercial valllecationic hydrophilic resinous condensation product which- It has been P p to treat W001 with acldified p is obtainable by (a) reacting a reactive functional dechlorite, to dechlorinate and then treat with an emulsion i i f a l lk l id i h a polyamine i d- Solution of a polymerized (ii-Olefin resin, a melamineproportions that a substantial proportion of the amine formaldehyde type resin or a urea or alkylated ureaformaldehycle type resin. Such a process is not, in our F fi X? E ESQQYQI.

- m: 0 3,580,701 w Patented May 25, 1971 experience, a satisfactory one for imparting shrink re 3,580,701 sistance to wool primarily-because the resins selected are unsuitable for the intended purpose and must inevitably unfavourably affect the electrostatic properties of the treated product and .thus render it more readily groups present in the polyamine remain unchanged and (b) then reacting the product thus produced with at least one bifunctional compound containing at least one group selected from epoxide and alpha-halo-beta-hydroxyalkyl groups, at least the latter part of the treatment being carried out under alkaline conditions, and heating the wool when impregnated with said condensation product.

In the first step of the present process the wool is subjected to a substantially uniform treatment with a substance which acts as a source of hypochlorous acid under acid conditions. The preferred reagent for the present purpose is an aqueous solution of an alkali metal dichloroisocyanurate to which an acid, e.g. a mineral acid, has been added. However, other sources of hypochlorous acid such as the solution obtained by dissolving dichloroisocyanuric acid in aqueous tetrasodium pyrophosphate and then acidifying such solution may be used. Another convenient procedure is to acidify an aqueous solution of an alkali metal hypochlorite or to add an aqueous solution of the hypochlorite to aqueous acid. Such treatments are known to be capable of imparting shrink resistance to wool per se but for the present purpose a limited degree of treatment is sufficient. The treatment should be sufficient to ensure that the surfaces of the wool fibres are substantially more easily wetted than are similar untreated fibres.

The extent of the treatment necessarily depends upon a number of factors such as the nature of the goods to which the treatment is being applied, e.g. wool in top form, a wool serge or knitwear, and the kind of Wool to which the treatment is to be applied. Some types of wool are converted to a shrink resistant form by a less severe chemical treatment than are others. In consequence, different kinds of woollen goods require different degrees of chemical pretreatment in order to render them receptive for the subsequent treatment with hydrophilic cationic polymer. As a rule the required degree of shrink resistance and receptivity are obtained when there is a reduction in shrinkage, when compared to a control, of about 50% determined upon the area (length in the case of tops) of the treated and untreated specimens. In the extreme case, however, a reduction of may be sufficient. Preferably the shrinkage is reduced by 60 or 70% when compared with that of an untreated control. Whilst the shrinkage may be reduced by the chemical treatment by more than 80% of that of a control, this is not usually necessary, since it is a feature of the invention that a substantial part of the shrink resistance is derived from the hydrophilic cationic polymer which is subsequently applied. The purpose of the uniform hypochlorous acid treatment is to modify the surfaces of the woollen substrate so that a much more uniform coverage is obtained when the hydrophilic polymer coating is applied: it also has the effect of enabling uniform coverage to be obtained without applying a heavy loading of the hydrophilic polymer.

It is also preferred that the hypochlorous acid treatment be applied from a short liquor bath. It is desirable for the present purpose that the modification of the fibres be confined as far as possible to the surfaces thereof and this is best secured by using as concentrated a bath of reagent as possible whilst supplying not substantially more of the source of hypochlorous acid than is required to produce the desired effect. A predetermined pickup can be secured by passing the woollen material undergoing treatment first through a short liquor bath and then through the nip of a pair of rollers adjusted to secure a pickup of the liquor of 50250%, preferably 80-130% of the weight of the woollen material undergoing treatment.

After treatment with the source of hypochlorous acid the woollen material may be further treated with an aqueous bath containing an alkali metal salt of sulphurous acid such as sodium sulphite in order to remove residual chlorine and substantially all the acidity.

The bath containing a source of hypochlorous acid may also contain permonosulphuric acid or an alkali metal salt thereof: such bath also has an acid pH value, pH values of 3-6 being preferred. In this case the combined treatment should result in a reduction in shrinkage, when compared to a control, of at least 15% and usually about 50% on the basis set forth above, and more preferably of 60 to This treatment gives a whiter product than that obtainable when the acid source of hypochlorous acid is used alone. A short liquor bath is also preferably used with such treatments.

The oxidising treatments described above are desirably carried out in the presence of a wetting a'gent, preferably a non-ionic wetting agent such as a water-soluble polyethanoxy-alkylphenol e.g. a condensation product of trimethylnonylphenol'with 6 moles of ethylene oxide.

At the conclusion of the treatments described above the treated woollen material should be thoroughly washed in water to remove traces of the chemicals used, and is then ready for treatment with the cationic hydrophilic resinous condensation product.

The cationic hydrophilic condensation products used are produced by the reaction of a reactive functional derivative of a polyalkylene oxide with a polyamine containing at least two amine nitrogen atoms each carrying a reactive hydrogen atom. The preferred polyamines are polyalkylene polyamines. Suitable amines include ethylene diamine, diethylene triamine, triethylene tetramine, dipropylene triamine, para-phenylene diamine and 1,4-diaminocyclohexane. The polyalkylene oxides such as polyethylene oxides and polypropylene oxides have terminal hydroxyl groups and these terminal groups are utilised to convert the oxides to reactive functional derivatives thereof, for example by reaction with an acid halide for example phosgene or chlorsulphonic acid or by reaction with bifunctional compounds containing an epoxide function and a halogen substitutent e.g. epichlorohydrin or similar function capable of forming an anion such as a sulphuric ester grouping. The polyalkylene oxides may have from 3 to 70' ethereal oxygen atoms and many have a molecular weight of from 400 to 2000. The chain of oxygen and carbon atoms present in such compounds may be interrupted by one or more urethane groups. Condensation between the polyamine and the reactive functional derivative of the polyalkylene oxide is conveniently effected by heating in the presence of a condensing agent such as boron trifiuoride or stannic chloride. The proportions of the reactants participating in this reaction must be such that there are sufficient amino groups available after completion of the reaction for a further reaction with epichlorohydrin, dichlorohydrin, or a compound containing epoxide and/ or alpha-halo-beta-hydroxyalkyl groups. The products of the first reaction are polyamines containing polyalkylene oxide residues and those derived from dipropylene triamine are particularly useful. To the product of the first reaction there is then added epichlorohydrin, dichlorohydrin and/ or another bifunctional compound containing epoxide and/ or alpha-halo-beta-hydroxyalkyl groups in the molecule e.g. a polyalkylene glycol bis-chlorohydrin ether, and the reaction mixture is heated, with or without the addition of alkali, until an increase in viscosity is observed. The product is then stabilised until required for use by the addition of an acid such as hydrochloric acid until the pH falls to 5.5-6.0.

In the process of the present invention aqueous solutions of cationic condensation products prepared by the above process, and especially those derived from polyalkylene oxides having a molecular weight of 600 to 2000 are used to treat woollen textile materials which have been previously treated as described above, at least the latter part of the treatment being carried out under alkaline conditions. The pH value of the bath is preferably 7-10, most preferably 8-8.5. The treated material is rinsed and then dried at raised tempeartures, e.g. 70120 C. The application of 2-3% of the condensation product and 13% of anionic wetting agent (if required) based upon the weight of the wool provides a soft finish and imparts to the wool a high degree of shrink resistance. A larger proportion of cationic condensation product can be used but in the case of woven materials, such as wool serge, is in general not necessary. The finish has a good hand and there is a marked improvement in the antistatic properties of the fibres when compared with untreated materials. In order to secure level treatment with the condensation product, the aqueous solution thereof may contain a suitable proportion of a wetting or levelling agent: a cationic or nonionic wetting agent is suitable for this purpose.

In batch processing heat treatment of the impregnated wool may take place in the bath in which the cationic condensation product is applied to the woollen substrate. This may be effected, for example, by raising the temperature of the bath before the pH thereof has been adjusted to at least 7.

According to a further feature of the invention the cationic condensation product may be applied to the wool in the presence of an anionic wetting agent, preferably the sodium salt of a sulphated fatty alcohol. When the treatment is carried out in this manner the risk of cross staining during normal washing treatments is reduced.

The treatments outlined above may be carried out continuously or as batch operations or one treatment may be a continuous operation and the other batch operation. The continuous treatment of wool with a solution containing a source of hypochlorous acid may be carried out as described in patent application No. 453,419, whilst that with a source of hypochlorous acid and permonosulphuric acid may be carried out as described in patent application No. 453,369. It will be understood however that the treatment with these reagents envisaged in accordance with the present invention involves reaction with a substantially smaller proportion thereof, based upon the weight of wool undergoing treatment, than that disclosed in the said applications. Continuous treatment with the cationic condensation products may be carried out by passing the previously treated woollen material through a bath containing condensation product and wetting or levelling agent in the desired proportions and then between the nip of a pair of rollers, the nip being adjusted to ensure takeup of a predetermined weight of the solution, e.g. 100% of the dry weight of the material passing. At the same time additional condensation product in a solution having an acid pH value and a solution of an alkaline-reacting material to raise the pH value to the desired value may be admitted to the bath so as to maintain a predetermined volume of liquor therein having a desired pH value and a substantially constant concentration of condensation prodnet.

The present invention aims at minimising the adverse effects of the oxidative shrink resist treatment of wool. It should be noted that the condensation product used in accordance with this invention, when applied to untreated wool at a practicable polymer level (e.g. up to solids), imparts little or no shrink resistance to the wool:'

this is shown in the examples which follow. The object of this invention is achieved by the use of a mild uniform oxidative chemical treatment followed by the uniform application of a low proportion of a particular kind of polymer. The effect of this two-stage process is to produce shrink resist wool with the minimum of chemical damage to the wool fibre whilst still maintaining substantially unchanged the handle and flexural properties of untreated wool.

An advantage of the invention is that the two-stage treatment produces wool material which may be laundered with negligible shrinking or felting. This shrink proofing effect is secured without detrimental efiFect upon the handle of the wool. In addition, the treatment involves only minimal degradation of the wool so that there is no significant loss of tensile strength, abrasion resistance, resiliency and elasticity. Moreover, since the polymer is hydrophilic, the treated wool displays excellent antistatic properties, can be dyed with wool dyes without difiiculty 6 and there is substantially no loss of the ability to absorb water vapour. An additional advantage is that the treated goods withstand dry-cleaning.

The following examples illustrate the process of the present invention. In a number of these examples the cationic condensation product used is one marketed under the trade name Nonax 1166 and is made by the procedure disclosed in British patent specification No. 880,897. This product contains a high proportion of polyethenoxy groups, a low percentage by weight of nitrogen, shows the presence of ionic chlorine and is marketed as a 50% by weight aqueous solution. All washing tests are carried out using the apparatus and method described by Gan, Textile Research Journal, volume 34, pages 945-953 (1964): the times of testing are specified.

EXAMPLE 1 (a) A water soluble cationic condensation product was prepared in the following manner:

To polyethylene glycol (mean molecular weight 600, 180 parts) was added tin tetrachloride (2.7 parts) at about 30 C. with stirring. After heating to 68-70 C., epichlorohydrin (56 parts) was added with continuous stirring and cooling to maintain the temperature between 6870 C. The mixture was stirred for a further hour at this temperature and gave a crude polyethylene glycolbis-chlorohydrin ether (240 parts).

To this crude chlorohydrin ether parts) was added with stirring dipropylene triamine (13.2 parts), water (50 parts) and 40% caustic soda solution (2 8 parts); the mixture was heated at the boil under reflux for 45 minutes. The remaining crude chlorohydrin ether (160 parts) was added with stirring to the reaction mixture followed by water (30 parts), the mixture being boiled for a further 20-30 minutes. The pH value of the viscous reaction product fell to 7.6.

The reaction product was then cooled whilst the pH value was lowered to 5.5-6 by the addition of 10% aqueous hydrochloric acid (45 parts) to yield a pale yellow, cloudy, highly viscous liquid (400 parts).

(b) Following the procedure described in patent application No. 453,369, worsted ser-ge was continuously treated with an aqueous solution containing 0.5% by weight of potassium hydrogen permonosulphate (equivalent to 0.39% permonosulphuric acid) 0.5% by weight of a nonionic wetting agent and 0.5 by weight of sodium dichloroisocyanurate. The material passed through the nip of a pair of rollers in which the pick up was adjusted to of the weight of the wool. The pH of this bath was substantially 3. After passing through the nip the treated wool was allowed to fall upon a brattice where it remained for 1.5 minutes. It was then passed through a 7.5% aqueous solution of sodium sulphite, rinsed in water and dried. A part of the thus treated wool serge was used for testing and the remainder further treated as described below.

(0) Material treated as described under (b) was passed through a bath containing 3.3% of solids by weight of the polymer prepared as described above under (a), the pH of which was adjusted to 8.5 with sodium carbonate solution, and then through a precision nip at which the take up was 75% of the weight of the dry goods. The take up of the polymer was thus 2.5%. The goods were then dried and heated to C. for 10 minutes.

Materials treated as described under (b) and (c) as well as a control were submitted to washing tests with th following results: 7

Area felting 7 EXAMPLE 2 '(a) Following the procedure described in patent application No. 453,419, worsted serge was continuously treated with an aqueous solution of sodium dichloroisocyanurate having a pH value of 3.5 containing 1.0% by weight of the water-soluble condensation product of trimethylnonylphenol with 6 moles of ethylene oxide (a non-ionic wetting agent). The pickup at the nip was adjusted so that the wool was treated with 0.6% of its weight of chlorine. After resting on a brattice or scray until at least 95% of the dichloroisocyanuric acid had been utilised, the treated material was passed through a 1% by weight aqueous sodium sulphite solution and rinsed with water. A part was dried and used for testing. The remainder was passed on for further treatment.

(b) Material treated as described under (a) was passed through a bath containing 3.3% solids by weight of Nonax 1166 and 1.3% by weight of sodium dodecyl sulphate, which bath had been adjusted to pH 8, and then through a nip at which the take-up was 75% of the weight of the dry goods. The take-up of the former was thus 2.5% and of the latter 1.0% of the weight of the goods. The goods were then dried and heated to 80 C. for 30 minutes.

Materials treated as described under ,(a) and (b) as well as a control were submitted to washing tests with the following results.

(a) Following the procedure described in patent application No. 453,369, worsted serge was continuously treated in an aqueous bath containing 0.5% by weight of potassium hydrogen permonosulphate (equivalent to 0.3% of permonosul-phuric acid), 0.5 by weight of the non-ionic wetting agent used in Example 1 and 0.50% by weight of sodium dichloroisocyanurate. The material passes through the nip of a pair of rollers in which the pickup is adjusted to 100% of the weight of the wool. The pH of this bath is substantially 3. After passing through the nip the treated wool is allowed to fall upon a brattice where it remains for 1.5 minutes. It is then passed through a 2% by Weight aqueous solution of sodium pyrophosphate, rinsed in water and dried. A part was used for testing and the remainder further treated as described below.

(b) Serge treated as described under (a) was passed through a similar bath to that used in Example 1(b) the pickup at the nip being 75% of the weight of the dry good. The goods were then dried and heated to 80 C. for 30 minutes.

Materials treated as described under (a) and (b) as well as a control and a sample given treatment (b) only were submitted to washing tests with the following results.

EXAMPLE 4 The procedure described in Example 3 was repeated with the sole exception that under (a) instead of passing the goods through a 2% solution of sodium pyrophosphate a 5% aqueous solution of sodium sulphite was used. On

submitting the goods to washing tests the following results were obtained.

Area felting shrinkage, percent 5 120 wash 240 wash Untreated serge 42. 5 71. 1 Treatment (a) only 19. 3 35. 8 Treatments (a) and (b) 1.1 3.1

10 Of particular significance are the results reported in EXAMPLE 5 The procedure described in Example 3 was repeated using continuous lengths of wool tops and an aqueous bath containing 0.9% by weight of potassium hydrogen permonosulphate, 0.5 by weight of the non-ionic wetting agent used in Example 2 and 0.90% of sodium dichloroisocyanurate. The pickup at the nip was 110% of the weight of the goods. On submitting the goods to 30 washing tests the following results were obtained.

Length felting shrinkage, percent min. 60 min. wash wash Untreated top 28 35 Treatment (a) only 13 16 Treatments (a) and (b) 8 9 EXAMPLE 6 The procedure described in Example 5 was repeated with the sole exception that instead of passing the tops through a 2% solution of sodium pyrophosphate, a 5% aqueous solution of sodium sulphite was used. On submitting the goods to washing tests, the following results were obtained.

Length felting shrinkage, percent 30 min. min. Wash wash 50 Untreated tops 28 36 Treatment (a) only 8 9 Treatments (a) and (b) 4 3 EXAMPLE 7 Worsted serge was treated as described under Example 1(a). The thus treated serge was then entered into a bath containing 5% solids by weight of Nonax 1166 and 3% by weight of sodium dodecyl sulphate which had been previously acidified to pH 4 with acetic acid. 25 litres of this bath was used for each kilogram of goods treated. The temperature of the bath was gradually raised to 80 C, and the pH was then raised to 8.5 by the addition of sodium carbonate. The goods were held in the bath for a further 20 minutes, then rinsed and dried. Samples of untreated serge, serge which had received only the first treatment and serge which had undergone both treatments were submitted to washing tests with the following results.

Area felting shrinkage, percent 120 wash 240 wash Untreated serge 35. 5 63. 1 Treatment (a) only 8.6 25.1 Treatments (a) and (b) 2. 8 2. 6

9 EXAMPLE 8 (a) Worsted serge was entered into a bath containing 0.23 gram of sodium dichloroisocyanurate, 0.23 gram of potassium hydrogen permonosulphate and 0.1 gram of the non-ionic wetting agent used in Example 2 per litre of bath, the pH of which bath had been adjusted to 5.4. A liquor ratio of 30:1 was used. The serge was held therein for 20 minutes at 25 C. after which the pH of the 'bath was reduced to 2 by the addition of sulphuric acid and the treatment continued for a further 20 minutes at 40 C. The fabric was next rinsed, then treated in a 0.3% by Length of test samples: 25.0 cms. Mounting tension: 6.0 grams Constant rate of extension: 10.0 cms./ min. Number of tests: 25

In the following table all results are the average of '25 tests and the coefiicient of variation is shown:

Breaking eient of Prcent cient of Work of cient of load variation extension variation rupture variation T t t (gms.) (percent) at break (percent) (cm.-gms.) (percent) t l, t e ted 449 7 12. 20 1 219 23 giiti i, iii eiij 40 8 18. 3 14 1: 287 2 Treatment (a) only 405 7 16. 6 18 1,302 27 Tm men 5 (a) y 439 s 22. 4 11747 24 Treatments (a) and (b) dyed Area felting shrinkage, percent 120' wash 240' wash Untreated serge 54. 1 88. 0 Treatment (a) only.- 20.4 64. 8 Treatments (a) and (b) 1. 4 4.5

(a) Knitted woollen garments were entered into a bath containing 0.60 gram of sodium dichloroiscyanurate, 0.30 gram of potassium hydrogen per-monosul'phate and 0.1 gram of an anionic wetting agent (sodium salt of a sulphated castor oil) per litre of bath. The pH of the bath was adjusted to 5.4 with sodium carbonate: A liquor ratio of 30:1 was used. The goods were held in'the bath for minutes at C., after which the pH of the bath was reduced to 2 by the addition of sulphuric acid and the treatment continued for a further '20 minutes at 40 C. The garments were rinsed, then treated 'in a 0.5% by weight aqueous solution of sodium sulphite for 20 minutes and finally rinsed again.

(b) The thus treated garments were then treated in a bath containing 5% solids by weight of Nonax 1166 and 3% by weight of sodium dodecyl sulphate which had been previously acidified to pH 4.5 with acetic acid. A liquor ratio. of 30:1 was used. The garments were entered into the bath at 40 C. and the temperature of the bath gradually raised to 80 C., during 20 minutes and held at this temperature for 5 minutes. The pH of the liquor was then raised to 8.5 by the addition of sodium carbonate and the garments held in the bath for a further 20 minutes and then rinsed and dried. Samples of the thus treated goods were submitted to tests set out below.

Untreated goods, goods which had been submitted to treatment (a) only, and goods which had been submitted to both treatment (a) and treatment (b) were then dyed in a bath containing the following per litre.

0.33 gram of Colour Index Acid Blue 126.

0.66 gram of monoammonium phosphate.

0.16 gram of sodium dodecyl sulphate.

0.16 gram of the non-ionic wetting agent used in Example l.

The pH of the bath was 6.5, a liquor ratio of 30:1 was employed, the goods were entered cold and the bath was brought to the boil and held thereat for 1 hour. The goods were then taken out, rinsed and dried. Samples of the thus treated goods were then submitted to tests set out below.

The above table reveals that both oxidation treatment and dyeing independently result in some diminution in the strength of woollen yarns but that these losses are overcome when the yarns are treated after oxidation, but prior to dyeing, with the cationic condensation products used in accordance with this invention. Moreover, such treatment results in an increased extension at break and that there is an increase of about 40% in the amount of work required to rupture.

EXAMPLE 10 (a) Wool serge was entered into a bath containing 0.44 gram/litre of formic acid and 0.66 gram/litre of the anionic wetting agent used in Example 9. A liquor ratio of 30:1 was used. .The serge was held in the bath at 25 C. for 5 minutes. An aqueous solution of sodium hypochlorite (200 mls.)" was prepared containing 0.15% w./v. of available chlorine. The sodium hypochlorite solution was gradually introduced into the bath over a period of 10 minutes. The serge was held in the bath for an additional period of 1-0 minutes, rinsed in water and treated in a bath containing '30 gms./litre of sodium sulphite for 10 minutes, and finally rinsed again.

(b) The thus treated serge was then further treated in a bath of Nonax 1166 in the manner described in Ex ample 6.

Samples were submitted to washing tests with the following results:

We claim:

1. A process for the production of a shrink-resistant wool which comprises (a) substantially uniformly treating wool with an aqueous solution of hypochlorous acid having a pH withirathe range of 2-6 and then removing residual chlorine and acidity by treatment with an aqueous solution of an alkali metal salt of sulphurous acid, (b) thereafter uniformly treating the oxidized wool with a small proportion of a water-soluble cationic hydrophilic resinous condensation product formed by the reaction of (i) a polyalkylene oxide selected from polyethylene and polypropylene oxides having a molecular weight of 400 to 2000 with (ii) a polyamine having at least two amine nitrogen atoms each carrying a reactive hydrogen atom, followed by condensation of the reaction product of (i) and (ii) with a compound containing an epoxide or alphahalo-beta-hydroxyalkyl group, at least the latter part of said treatment with said cationic condensation product 1 1 being carried out at a pH within the range of 7-10, and (c) heating the thus treated material to 70120 C.

2. A process as claimed in claim 1 in which the source of hypochlorous acid is an acidified aqueous solution of an alkali metal dichloroisocyanurate.

3. A process as claimed in claim 1 in which the aqueous solution of hypochlorous acid also contains permonosulphuric acid or an alkali metal salt thereof.

4. A process as claimed in claim 1 in which the hypochlorous acid treatment is given from a short liquor bath.

5. A process as claimed in claim 1 in which the treatment with hypochlorous acid is one which produces a reduction in shrinkage, when compared with an untreated control, of 50 to 80%.

6. A process as claimed in claim 1 in which the weight of said cationic hydrophilic condensation product impregnated upon said wool is 2-3% of the weight of the wool undergoing treatment.

7. A process as claimed in claim 1 in which impregnation with said cationic hydrophilic condensation product is carried out in the presence of an anionic wetting agent.

8. A process according to claim 1 wherein the polyamine is a polyalkylene polyamine.

9. The process according to claim 1 wherein the polyamine is a member selected from the group consisting of ethylene diamine, diethylenetriamine, triethylenetetramine, dipropylene triamine, para-phenylenediamine and 1,4-diaminocyclohexane.

10. The process according to claim 1 wherein the compound containing epoxide or alpha-halo-beta-hydroxyalkyl groups is selected from the groups consisting of epichlorohydrin, dichlorohydrin, and a polyalkylene glycol 'bis-chlorohydrin ether.

11. A process according to claim 1 wherein at least said latter part of said treatment with cationic condensation product is carried out at pH 8.0 to 8.5.

12. A process according to claim 1 wherein the extent of hypochlorous acid treatment is such that there is a reduction in shrinkage of 15 to 80%.

13. The product of the process of claim 1.

References Cited UNITED STATES PATENTS 2,701,178 2/1955 Fell 8128 2,933,366 4/1960 Coe 8l28 2,909,448 10/ 1959 Schroeder 117-141 FOREIGN PATENTS 880,897 10/1961 Great Britain.

GEORGE F. LESMES, Primary Examiner P. C. IVES, Assistant Examiner US. Cl. X.R. 8-108, 115.6, 128 

